Platelet functions in patients with aortic ball valves

Area of Science:

• Cardiovascular Science
• Hematology
• Biomaterials Science

Background:

• Mechanical heart valves, specifically Staff-Edwards aortic ball valves, can impact blood components.
• Understanding alterations in platelet function is crucial for managing patients with prosthetic heart valves.

Purpose of the Study:

• To investigate the effects of Staff-Edwards aortic ball valves (series 1200 and 2300) on various platelet functions.
• To correlate changes in platelet function with clinical outcomes like hemolysis and bleeding time.

Main Methods:

• Studied platelet adhesiveness using Hellem's modified method.
• Measured serum lactate dehydrogenase (LDH) levels to assess intravascular hemolysis.
• Assessed platelet counts, aggregation (induced by collagen/epinephrine), and platelet survival.

Main Results:

• Significantly reduced platelet adhesiveness in patients with both valve types (50.9% for type 1200, 27.2% for type 2300) compared to normal subjects (71.8%).
• Inverse correlation between platelet adhesiveness and serum LDH levels, indicating mechanical damage.
• Prolonged bleeding time in type 2300 patients, inversely correlated with platelet adhesiveness.

Conclusions:

• Mechanical damage to platelets by the aortic ball valve is the primary cause of altered platelet reactivity.
• Disturbed platelet function may predispose to bleeding complications but could offer protection against arterial thromboembolism.
• Platelet function alterations were similar in patients with and without a history of thromboembolic complications.